1. Technical Field
The present invention relates to the general art of boots and shoes, and to the particular field of impact absorbing and energy return mechanisms associated with boots and shoes.
2. Prior Art
It has long been known, that when people walk, jog, or run, a significant percentage of their forward kinetic energy is wasted and lost. This loss results in shock which is caused by a person's foot impacting with the ground. How to store and release this energy loss is the overall problem. Existing devices involve an assemblage of different types of springs adhered to the base of a shoe. Generally, the higher the assemblage elevates a user's foot above the ground, the more thrust imparted to the user. This fact leads to a problem with lateral stability. Generally, the higher a user's foot is elevated above the ground, the easier it will be for a user to twist an ankle. Coil springs are inherently unstable in a lateral direction causing unwanted sidesway, especially upon release. Devices that employ a group of coil springs arranged under a shoe generally lack adequate lateral stability and may pose a safety risk.
Some examples of different spring devices are found in:    U.S. Pat. No. 5,517,769Spring-Loaded Snap-Type Shoe
The patent recognizes that a significant increase in performance requires a system to hold the energy loaded during heel-strike and release during step-off. The disclosed system used a ratchet to hold the loaded spring and triggers its release by bending the toe section of the shoe. Thus, this system attempts to time the release of energy during step-off.
(1) This system provides neither an optimum nor precise timing for energy release. The optimum timing of energy release occurs immediately following the decrease force during step-off. The system releases the loaded spring when the user bends at the ball of the foot which is not necessarily during and perhaps never at the optimum time.
(2) The system also returns energy to the heel alone. This is not ideal because the heel is not in contact with the ground during step-off.
(3) The system also requires a hollow cavity extending the length of the foot for the containment of the ratchet and spring system.    U.S. Pat. No. 4,936,030Energy Efficient Running Shoe
This patent recognizes that an increase in performance requires a system to hold the energy loaded during heel-strike and release it from the ball or toe region during step-off. This system uses a ratchet to hold the loaded spring and triggers its release by bending the toe section of the shoe. The system also attempts to transfer the forces from the heel to the toe via a series of complex levers and shafts.
(1) This system provides neither an optimum nor precise timing for energy release. The optimum timing of energy release is immediately following ball peak-force during step-off. The system releases the loaded spring either: 1) when said spring reaches a certain and fixed degree of compression, 2) when said spring reaches the limit of compression during push-off, or 3) after a fixed time delay. Although the patent neither explains not diagrams the process by which it accomplishes (2) or (3), these methods are inadequate and not optimal. The first and third processes are based on fixed criteria and cannot adapt to the variable forces and time periods during normal running. The second process is inadequate because it releases the spring prematurely. A user, during a turn or stop may load the forces on his forefoot at constant level before he has picked his final direction. This process therefore, can cause the user to lose control.
(2) The system does not guarantee nor does it disclose that the ball and heel will compress in a parallel manner. This is because of the number of parts, the complexity of design and the looseness of the system.    U.S. Pat. No. 6,029,374
Shoe and Foot Prosthesis with Bending Beam Spring Structures This structure attempts to address the simplicity and efficiency of carbon fiber bending beam springs. This structure also attempts to address the need for both heel and toe springs that prevent lateral movement. This structure is inadequate for some of the following reasons: 1) It does not provide a strictly parallel postured upper and lower sole and thus it cannot return more than half the user's weight, 2) it does not provide a parallel upper and lower toe sole and therefore depends on a tapered leaf spring for traction and control which does not provide either in an optimum way, 3) it does not provide a hold and release system (HRS) that limits the combined load forces of the springs to approximately the user's weight.    Patent Number WO 01/05469A1 (German and International Patent)Device for Helping a Person to Walk
1) It does not provide a strictly parallel postured upper and lower sole of normal length nor does it provide a parallel upper and lower sole toe and therefore does not provide adequate balance and control, 2) it does not provide a longitudinally pivoting lower sole and therefore does not allow for adequate agility, 3) it does not address HRS and therefore limits the efficiency of the springs, and 4) each boot weighs approximately 20 pounds which dramatically slows the foot-speed of the user and therefore overall running speed.